A light emitting diode (LED) is a cold light emitting device. A light emission principle of an LED is that, a forward bias (current) is applied on a III-V compound semiconductor material, electrons and holes in a diode are combined to convert energy into a form of light, and light is emitted when the energy is released. An LED features advantages of having small volume, long durability, low driving voltage, fast response speed, outstanding shock resistance, and adaptively to requirements of being light and compact as well as adaptively to miniaturization, and has long become a common product in the daily lives.
When used in an application with a high brightness level over an extended period of time, such as outdoor billboards, brake lights and traffic lights, an LED remains in a high temperature environment due to the extended application period, and the durability of a material of the LED is rapidly shortened also due to the high temperature environment. Thus, when an LED is packaged, how to quickly dissipate heat needs to be taken into account so as to increase the durability of the LED.
For example, the Taiwan Patent No. I438948 discloses an LED package structure, in which each of a positive electrode and a negative electrode is wired to electrically connected to an electrical connection portion, which is for soldering onto a substrate. To satisfy heat dissipation needs, a heat dissipation portion (cooling fins) is provided on each of the two electrical connection portions, thus quickly dissipate heat and enhancing the heat dissipation effect through the cooling fins.
However, in the above prior art, to meet heat dissipation needs, cooling fins that use up a considerable volume are used. These cooling fins provided, although achieving the object of heat dissipation, hinder LEDs from being arranged close to one another, resulting in an insufficient intensity of illumination that fails to meet requirements of applications needing extremely high light intensity, e.g., vehicle headlights and projectors. Further, it is also challenging to integrate multiple LEDs having different output wavelengths into one LED to satisfy the need of an output of multiple wavelength light sources.